WordPress Image/Gravator Not Showing

Hi – All of a sudden my profile image/gravatar that appears in the upper right corner of the admin box for wordpress is not there. When I published a post this morning, I was just a ghost icon. Anyone know why this happened? I checked my wordpress.com account and it is still there. I switched to a hosted site about a month ago but it was showing up in all my email notifications/posts. This just started yesterday.

Melissa